It seems to me that a lot of people on HN are assuming that this design is an intentional rip-off. It's entirely possible that whoever did the icon didn't realize that they had seen a clock like that before and thus didn't realize they might infringe on someone else's trademark.
Indeed. I don't know much about the designer subculture, but there are a bunch of "iconic" industrial designs that they (should) know about. Another famous one is the IBM wall clock: http://vimeo.com/40953003 (one of the Windows clock gadgets is obviously inspired by it).
(Disclaimer: I am not an Apple fan.)
As for the design itself, there is the blatant copying of the seconds hand, but otherwise it seems whoever did it took some care to differentiate the apple clock from the original. E.g. how the lengths of the hour and minute hands relate to the radius of the clock and the size of the hour and minute tick marks. Then of course there are obvious implications of being viewed on a tiny 4" screen. Whether that is enough to build a legal defense on, I have no idea.
They should just license it. I think all the people who are saying it's analogous to the Apple/Samsung debacle are reaching though. No one is going to walk into a store with the intent of buying a Mondaine watch and leave with an iPhone instead.